Fuel-pump.



H. LEMP.

FUEL PUMP.

APPLICATION FILED AUG. 23, 1912.

1 1 1 2,299, Patented Sept. 29, 1914.

2 SHEETS-"SHEET 1.

F'igl..

Witnfsses Inventor;

7% g y Her-mann Lemp,

H. LEMP.

FUEL PUMP.

APPLICATION FILED AUG.23,1912.

1,112,299. Peteetet sept. 2e, tete.

2 SHEETS-SHEET 2.

0 Fig. 2QY

1X Hermann Lemp t tete @te I following is a specification.

or `cylinders is directly dependent upon the lio , Fig/l is a section of the variable contact switchen the line 4 4, 2; and Fig. 5 is*v plungers 2 being secured to a cross-head 3 pas .suction valve or valves is or are controlled STATES!- UFICE;

HERMANN LEM?, of" LYNN,l Massacusnr'rs; As'sIeNoRro eerzivniaar,v Enr-:orare y COMPANY, A cenroree'vrrorr4 oF NEW vom;v

' -FUELJUMPQ To all 'whom it may concern:

Be it known that I, HERMANN LEMP, -a' citizen of the United States, residing at Lynn, county of Essex, State of Massachu-4 setts, have invented certain new and useful Improvements Fuel-Pumps, of which the This invention relates to pumps for sup'- plying liquid fuel to internal combustion engines, and more especially to that type of, engine wherein the compression of the aix" in the cylinder produces so high a temperature that the fuel charge is ignited when vit is injected into the cylinder. -K

The object of he invention is to provide an improved mode of regulating the ump which delivers the fuel to the cylin er orcylinders of the engine, so that the' quantity. delivered will vary with the load. To this end a pump is used in which the plunger, or each of the several plungers, displaces a fixed volumeof fuel at every stroke, but the suction valve or valves can beheld open for a longer or shorter time during the forcing stroke of the pump so that a portion 'of the fuel can find its. way back to the supplyl tank instead yof going tol the engine. The

by the speed governor of the engine, so thatv the fuel actually delivered to the cylinder speed, being increased when the speed drops fl', andvice versa. f

The present invention resides v-in the special devicesfor effecting this control, which is accomplished electrically.

In the accompanying. drawings, Figure 1 is an elevation of 'a portion of an internal 'combustion engine -embodying my inven-y tion; Fig. 2 is an elevation at ri ht angles to Fig. 1; Fig. 3 is a section' of t e pump;4

a diagram ofy circuits. ,l

It is assumed that the enginllillustrated has three cylinders, each supplied `Vwith` liquid fuel by its .own pump,l the several which is reciprocated by a rod 4 and'eccentric 5. A shaft `6`carr1es the eccentric and is provided with a ar 7 which meshes with another gear 8 on is uprightpshaft 9 which drives the speed governor 10.

The pumxsA are all alike, so'- that a description o one will suflce for al1. The

flows:-

stant quantity of fuel at each stroke, I ffth'e v110 g Spe0ili0n f Letters raient? I Patented Sept. 29;'1914. 'Application med Aagust'zs, 1912. semaine. 716,669.

1n the top of the casing- 12.-- A check valve 13 preventsv any return of the fuel foeced into the delivery pipe 14, which runs to the A set .screw 21 in said'arm determines the polnt 1n its movement where contact with the valve stem.

up through the top of the'cas'ing 1n line with an arm v19 on a rock-shaft 201v it comes in l plungenr 2 worksthrougha'stuilng box 11."

On the rock-shaft 20 is `an arm 22 to which is' pivoted the movable core 23 of a solenoid 24. A variable'contact switch 'con-v trolled by the-speed governor operates to energizethis solenoid at theproper times to pull down the rock-arml19'and holdvthe suction ,valve open. The' switch preferably. comprises a cylinder 25 mounted on the shaft 6 and composed of conducting andA nonfconducting segments a, b unitedona diagonal plane.` Two brushes 26, 2'( 'stand side by side, one bearing on a collecting'iing on the shaft 6 and the other on thesurface of the cylinder 25. Said cylinder and the j preferably brush 27 are relatively movable ;v by means of the following construction: The brushes are secured to hubs 28, mounted onbut insulated .from a short shaft 30 supported in the arms 29, which are l of alfork 31ron a bracket secured to the frame ofthe en 'n'e.' 4

nThe h ub 28 is stationary, but 'the h u' 29 carrying the brush 27 can slide -along said shaft 30, which is preferably Vsquared to keep the brush always in close contact with the cylinder 25. A link 32 is pivoted to the hub 29 and'to an arm 33 on a rock-shaft 34,

which has another arm 35 connected by a rod 36 and a lever 37 with the slidingv collar "38,'whi ch is caused toI rise andf'a'll on the shaft 9 'by'the movement of they-'governor we' hts.fv

e two brushes 26, -27 are connected by wires 39, 40 with the terminals 'of' thesole-` oid 24.- .,A battery 41 or othersour'ce of ciirrentis connectedtq the wireflandto Y the middlep'iointof said solenoid,` which is preferably iferentiadlfjwound; though a sim le solenoid/worin fromei`1`d\tolY end cou d be used if desired The .differential\\\-\ winding prevents sparking at thebrl'lsb'es.

The o ration of th device is asljfole pump plungers displace'a -iongovernor will slide the' brush 27 over to the load' is heavy, the governor keeps thel brush 27.011 that part of the cylinder 25where the 1 angular width of the conducting segment a is short, and consquently the length of time of energization of the solenoid 24 will be short, so that during most ofthe forcing strokeof the pump, the suction valves will remain closed and the greater part of the 1 fuel ,will be sent to the engine.

load drops, and the engine speeds up, the

left in Fig. 2, so that a wider part of the conducting segment is engaged, and the circuit is kept' closed .during a greater portionI of the forcing stroke. Thismeans that the energizationof the solenoid lasts longer, and

consequently the depressionl ofthe suction valves is maintained for a longer portion of less goes to the engine, thereby slowing itv thel forcing stroke, so that more of the fuel is allowed to return to the supply tank and down.

Inl accordance with'the provisions of the patent statutes, I have described the principle of operation of my invention together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the appara-tus shown is only illustrative, and that the invention can be carried out by other means.

f `What I claim as new and desire to secure Letters'Iatent of the United States,

`1. The combination with an internal com- But if the` bustion engine, of a fuel pump having a constant stroke, a suction valve therefor, a solenoid for holding said valve open, a rotary switch having a conducting segment of varying width, a relatively movable brush cooperating therewith, and a speed governor adapted to vary the point of contact between said switch and said brush. 4

2. The combination with an internal combustion engine, of a fuel pump having a constant stroke, a suction valve therefor, a

lsolenoid for holding-said valve open, a rotary switch operating in synchronism with lsaid -pump and consisting of a cylinder having a conducting segmentSof varying width,

a brush movable along said cylinder, and a speed governor adapted to move said brush.

3. The combination with an internal combustion engine, of a fuel pump having a constant stroke, a suction Vvalve therefor 

